Mass Outflows from Stars and Galactic Nuclei

Mass Outflows from Stars and Galactic Nuclei PDF Author: Luciana Bianchi
Publisher: Springer Science & Business Media
ISBN: 9400929412
Category : Science
Languages : en
Pages : 427

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Book Description
The objective of this workshop was to put together observational and theoretical works on outflows from different kinds of astrophysical objects, occurring on different scales and at various evolutionary phases, and to discuss the impact of observations from future space missions. For the stars, we thought to follow throughout the evolution the relevance (rates and dynamical rrodes) of the mass loss phenomenon, e. g. to explain how and when massive stars loose most of their ini tial mass to end up with typical WD masses. The observations of the solar wind were included for being a unique case where the origin and propagation of the outflow can be resolved. We thought that the comparison with similar phenomena occurring in galactic outflows would be fruitful, as demonstrated by recent works on galactic winds and jets. The interest of having this workshop in Torino came because there are groups in this area, at the Astronomical Observatory and at the Institute of Physics of the University, involved in the theoretical and observational studies of outflows from astrophysical objects. The members of the Scientific Organizing Conmi ttee were: V. Castellani, C. Cesarski, P. Conti, A. Ferrari, A. Gabriel, M. Grewing, Y. Kondo, H. Lamers, V. Manno, M. Rees and R. Schilizzi. The Local Organizing Conmi ttee was: L. Bianchi, G. Massone and E. Antonucci. During the workshop the following topics were treated: the solar wind, the mass loss from cool stars and from hot stars (m. s.

Mass Outflows from Stars and Galactic Nuclei

Mass Outflows from Stars and Galactic Nuclei PDF Author: Luciana Bianchi
Publisher: Springer Science & Business Media
ISBN: 9400929412
Category : Science
Languages : en
Pages : 427

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Book Description
The objective of this workshop was to put together observational and theoretical works on outflows from different kinds of astrophysical objects, occurring on different scales and at various evolutionary phases, and to discuss the impact of observations from future space missions. For the stars, we thought to follow throughout the evolution the relevance (rates and dynamical rrodes) of the mass loss phenomenon, e. g. to explain how and when massive stars loose most of their ini tial mass to end up with typical WD masses. The observations of the solar wind were included for being a unique case where the origin and propagation of the outflow can be resolved. We thought that the comparison with similar phenomena occurring in galactic outflows would be fruitful, as demonstrated by recent works on galactic winds and jets. The interest of having this workshop in Torino came because there are groups in this area, at the Astronomical Observatory and at the Institute of Physics of the University, involved in the theoretical and observational studies of outflows from astrophysical objects. The members of the Scientific Organizing Conmi ttee were: V. Castellani, C. Cesarski, P. Conti, A. Ferrari, A. Gabriel, M. Grewing, Y. Kondo, H. Lamers, V. Manno, M. Rees and R. Schilizzi. The Local Organizing Conmi ttee was: L. Bianchi, G. Massone and E. Antonucci. During the workshop the following topics were treated: the solar wind, the mass loss from cool stars and from hot stars (m. s.

Mass Outflows from Stars and Galactic Nuclei

Mass Outflows from Stars and Galactic Nuclei PDF Author: Luciana Bianchi
Publisher:
ISBN:
Category : Galactic nuclei
Languages : en
Pages : 440

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Book Description


Mass Outflow in Active Galactic Nuclei

Mass Outflow in Active Galactic Nuclei PDF Author: D. Michael Crenshaw
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 562

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Book Description
Annotation Proceedings of a March 2001 workshop held in Washington, D.C., bringing together an international group of researchers to share new developments in the field during the last four years. Fifty-seven contributions are arranged in sections on X-ray absorption and emission; intrinsic UV absorption; broad absorption-line QSOs; narrow- line region, broad-line region and jets; and kinematics and dynamical models. A sampling of topics: high-resolution X-ray spectroscopy of the warm gas in Seyfert 1 galaxies, observations of warm absorbers in AGN, radio-selected broad absorption line quasars, the importance of shocks in the ionization of the narrow line region of Seyferts, and strong shocks and supersonic winds in homogeneous media. Indexed by author and object, but not by subject. Annotation c. Book News, Inc., Portland, OR (booknews.com)

The Interplay Among Black Holes, Stars and ISM in Galactic Nuclei (IAU S222)

The Interplay Among Black Holes, Stars and ISM in Galactic Nuclei (IAU S222) PDF Author: International Astronomical Union. Symposium
Publisher: Cambridge University Press
ISBN: 9780521848039
Category : Science
Languages : en
Pages : 608

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Book Description
How massive are the largest and smallest nuclear black holes in galaxies? Why are the masses of nuclear black holes proportional to those of their host galaxy bulges? How is nuclear activity triggered? What are the observational signatures of such processes? What are the connections between the active nucleus, stars and interstellar medium in galaxies? Answers to these questions are addressed in this book, which presents a compilation of 191 works covering recent observations from X-rays to radio wavelengths, as well as theoretical modeling of accretion disks, stellar populations and galaxy and black hole evolution. This volume presents the nuclear activity as a phase in the life of a galaxy, which is intimately connected to the evolution of its stars and interstellar medium. It brings together recent developments in topics covering most aspects of galaxy evolution, and is a valuable resource for astronomers and graduate students working in extragalactic astronomy.

Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies

Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies PDF Author: Mitchell D. Revalski
Publisher:
ISBN:
Category : Accretion (Astrophysics)
Languages : en
Pages : 180

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Book Description
Observations reveal that supermassive black holes (SMBHs) grow through the accretion of gas at the centers of galaxies as luminous active galactic nuclei (AGN), releasing radiation that drives powerful outflows of ionized and molecular gas. These winds are thought to play a critical role in galaxy evolution by regulating star formation and the growth of galaxies and their SMBHs. To test this model, we must quantify the dynamic impact of outflows by measuring their mass outflow rates and energetics. Using spatially resolved spectroscopy and imaging from the Hubble Space Telescope and Cloudy photoionization models we mapped the ionized gas kinematics and mass distributions of narrow line region (NLR) outflows in nearby active galaxies. We find that the outflows contain up to several million solar masses of ionized gas and are limited to distances of 1 - 2 kiloparsecs from the nucleus. The maximum mass outflow rates are M = 3 - 12 solar masses per year and the outflow gas mass, velocity, radial extent, and energetics are positively correlated with AGN luminosity. We use our results to test simplified techniques with less stringent data requirements and find that they significantly overestimate the gas mass. These results are crucial for modeling powerful outflows at higher redshift that may considerably influence star formation rates and the formation of galactic structure.

Reviews in Modern Astronomy

Reviews in Modern Astronomy PDF Author: Gerhard Klare
Publisher: Springer Science & Business Media
ISBN: 3642775438
Category : Science
Languages : en
Pages : 279

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Book Description
The International Scientific Spring Meeting of the Astronomische Ge sellschaft (AG) held at Bamberg in April 1991 was devoted to "Vari abilities in Stars and Galaxies". Time-dependent phenomena are observed in a wide range of as tronomical objects. They are caused by different physical mechanisms (for example by pulsation, by accretion, or by dramatic eruptive events in connection with mass outflow) producing observable intensity vari ations through all wavelengths. Many of the papers in this volume are concerned with galactic stars showing such behaviour (for ex ample cataclysmic variables, symbiotic stars, luminous blue variables (LBVs) and novae). Intrinsic variations of the, magnetic field struc ture on observable time scales are, for instance, a peculiarity of cool, solar-like stars and represent a useful tool to study differential rotation and cycles of activity. Recent results on the investigation of gas motions in the inner regions of the Milky Way system, a study of the bipolar galaxy M 82, observations of variable extragalactic radio sources, the variability of emission lines in active galactic nuclei (AGN) as well as continuum variations of quasars and AGN are discussed by several authors. The yearbook series Reviews in Modern Astronomy of the AG to bring the scientific events of the was established in 1988 in order meetings of the society to the attention of the worldwide astronomical community.

Photoionization Modelling as a Density Diagnostic of Line Emitting/Absorbing Regions in Active Galactic Nuclei

Photoionization Modelling as a Density Diagnostic of Line Emitting/Absorbing Regions in Active Galactic Nuclei PDF Author: Tek Prasad Adhikari
Publisher: Springer
ISBN: 3030227375
Category : Science
Languages : en
Pages : 126

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Book Description
This book presents timely work on the nature of the physical processes underpinning two of the basic characteristics of the gas structure in the innermost region of Active Galactic Nuclei (AGN): ionized outflows and emission line regions. In addition, it describes physics-based methods for estimating the density of the astrophysical plasma surrounding AGN. All numerical computations of the photoionized gas employ the most advanced codes available (CLOUDY and TITAN). Calculations of the radiative transfer are based on the assumption of thermal and ionization equilibrium. Promising preliminary examples of comparison with current observations are included for several individual AGN. All of them suggest that the absorbing/emitting gas should have a density on the order of 1012 cm-3. Future observations will provide more objects to verify these results, and will allow us to put constraints on the launch radius of ionized outflows and therefore on the mass loading and kinetic energy outflow rates. These rates, in turn, are crucial to estimating whether the outflows have a significant feedback impact on star formation and metal enrichment in the interstellar medium of the host galaxy. In closing, the book discusses a representative example of applying powerful photoionization techniques to explain the complex physics of the AGN environment.

Observational Constraints on the Influence of Active Galactic Nuclei on the Evolution of Galaxies

Observational Constraints on the Influence of Active Galactic Nuclei on the Evolution of Galaxies PDF Author: Christopher Mark Harrison
Publisher: Springer
ISBN: 3319284541
Category : Science
Languages : en
Pages : 208

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Book Description
This prize-winning Ph.D. thesis by Chris Harrison adopts a multi-faceted approach to address the lack of decisive observational evidence, utilising large observational data sets from several world-leading telescopes. Developing several novel observational techniques, Harrison demonstrated that energetic winds driven by Active Galactic Nuclei (AGN) are found in a large number of galaxies, with properties in agreement with model predictions. One of the key unsolved problems in astrophysics is understanding the influence of AGN, the sites of growing supermassive black holes, on the evolution of galaxies. Leading theoretical models predict that AGN drive energetic winds into galaxies, regulating the formation of stars. However, until now, we have lacked the decisive observational evidence to confirm or refute these key predictions. Careful selection of targets allowed Harrison, to reliably place these detailed observations into the context of the overall galaxy population. However, in disagreement with the model predictions, Harrison showed that AGN have little global effect on star formation in galaxies. Theoretical models are now left with the challenge of explaining these results.

The Molecular Astrophysics of Stars and Galaxies

The Molecular Astrophysics of Stars and Galaxies PDF Author: T. W. Hartquist
Publisher: Oxford University Press
ISBN: 9780198501589
Category : Galaxies
Languages : en
Pages : 562

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Book Description
This book provides a comprehensive survey of modern molecular astrophysics. It includes an introduction to molecular spectroscopy and then addresses the main areas of current molecular astrophysics, including galaxy formation, star forming regions, mass loss from young as well as highlyevolved stars and supernovae, starburst galaxies plus the tori and discs near the central engines of active galactic nuclei. All chapters have been written by invited authors who are acknowledged experts in their fields. The thorough editorial process has ensured a uniformly high standard ofexposition and a coherent style. The book is unique in giving a detailed view of its wide-ranging subject. It will provide the standard introduction for research students in molecular astrophysics. The book will be read by research astronomers and astrophysicists who wish to broaden the basis oftheir knowledge or are moving their activities into this burgeoning field. It will enable chemists to learn the astrophysics most related to chemistry as well as instruct physicists about the molecular processes most important in astronomy.

Mass-Transfer Induced Activity in Galaxies

Mass-Transfer Induced Activity in Galaxies PDF Author: Isaac Shlosman
Publisher: Cambridge University Press
ISBN: 9780521543309
Category : Science
Languages : en
Pages : 534

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Book Description
How gas flows and starbursts light up active galaxies.